Mesa (master): glsl: Fix the foreach_in_list_reverse macro.

[Kenneth Graunke]

Module: Mesa
Branch: master
Commit: e13a6406c3d55162d6f4641f3ccca7635b9a5212
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=e13a6406c3d55162d6f4641f3ccca7635b9a5212

Author: Kenneth Graunke <kenneth at whitecape.org>
Date:   Sat Jul  5 22:04:45 2014 -0700

glsl: Fix the foreach_in_list_reverse macro.

We clearly don't want to start at the head and walk backwards; we want
to start at the last real element before the tail sentinel.  If the list
is empty, tail_pred will be the head sentinel, and we'll stop.

Nothing uses this function, so I guess nobody noticed it was broken.

Signed-off-by: Kenneth Graunke <kenneth at whitecape.org>
Reviewed-by: Matt Turner <mattst88 at gmail.com>

---

 src/glsl/list.h |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/glsl/list.h b/src/glsl/list.h
index 922bd68..a4444bd 100644
--- a/src/glsl/list.h
+++ b/src/glsl/list.h
@@ -565,9 +565,9 @@ inline void exec_node::insert_before(exec_list *before)
         !(__inst)->is_tail_sentinel();               \
         (__inst) = (__type *)(__inst)->next)
 
-#define foreach_in_list_reverse(__type, __inst, __list) \
-   for (__type *(__inst) = (__type *)(__list)->head;    \
-        !(__inst)->is_head_sentinel();                  \
+#define foreach_in_list_reverse(__type, __inst, __list)   \
+   for (__type *(__inst) = (__type *)(__list)->tail_pred; \
+        !(__inst)->is_head_sentinel();                    \
         (__inst) = (__type *)(__inst)->prev)
 
 /**